Conventionally, a clean bench is often used as an apparatus for improving air cleanliness of a local work space. In a typical clean bench, on only a front side of a working table is provided an opening for work, and sides thereof other than the front side form an enclosure in order to maintain cleanliness. In such a clean bench, a clean air blowing outlet is arranged within the enclosure, and a worker puts his or her hands therein from the front opening for work and then performs the work.
However, the opening for work in the clean bench is narrow. Accordingly, there is a problem in terms of workability when workers perform assembly work of a precision instrument or the like. In addition, as in a production line, when work involves transfer of manufactured products or manufactured components, procedures such as arranging the entire line in the clean room have been taken. However, this leads to a problem with large-scale equipment.
Thus, a local air cleaning apparatus has been proposed in which air flow opening faces of a pair of push hoods that can blow out a uniform flow of cleaned air are arranged opposite to each other to cause air flows from the each air flow opening face to collide with each other, thereby being able to make a region between the pair of push hoods a clean air space having a higher level of cleanliness than in other regions (Patent Literature 1).